The present invention relates to a medical instrument, in particular a surgical instrument, with an intervention portion for a medical intervention, and with a handle designed for holding the instrument, with a handle surface portion which has an arrangement with shapings and, formed between the shapings, enclosure portions.
Numerous medical instruments are known from the prior art. Along a longitudinal axis of the medical instrument, an intervention portion for a medical, in particular surgical or microsurgical, intervention is arranged at a distal end (remote from the surgeon) of the medical instrument, also known as the instrument tip, and a handle is arranged at a proximal end of the medical instrument.
On account of hygiene regulations, these instruments are usually produced entirely from stainless metal, generally chrome vanadium, stainless steel or titanium, which has a smooth surface structure without introduced depressions or elevations.
In order that the surgeon can handle the medical instrument and in particular the intervention portion readily for the medical intervention without the surgeon's hand or finger, manipulating the medical instrument, slipping off the medical instrument, the medical instruments are provided with a handle having a handle surface portion.
In a first type of medical instruments configured in a generic manner, the handle surface portion has, as shapings, elongate grooves milled into a surface of the handle, between which the remaining material, which has not been milled away, of the surface of the handle forms raised elongate ribs as enclosure portions. In this case, the deep grooves frequently each have a pyramid shape with a triangular cross-sectional profile, such that a right angle is defined between the cross-sectional profiles of adjacent grooves. These grooves and ribs can prevent the hand, and in particular the force-applying thumb, of the surgeon from slipping off particularly effectively when they are arranged such that their respective longitudinal directions define an angle of 60 degrees with the longitudinal axis of the medical instrument. Then, the grooves and ribs are oriented perpendicularly to a longitudinal axis of the thumb to be applied to the handle, the longitudinal axis of which thumb defines an angle of 30 degrees with the longitudinal axis of the instrument in conventional medical instruments.
In a second type of medical instruments configured in a generic manner, the handle surface portion has, as shapings, a first group of mutually parallel elongate grooves and a second group of mutually parallel elongate grooves in the surface of the handle, wherein the grooves of the first group define a right angle with the grooves of the second group. The remaining material, which has not been milled away, of the surface of the handle, which material is bounded by the grooves of the two groups, forms a structure of raised rectangular lands.
Particularly high demands are imposed on medical and in particular surgical instruments with regard to their cleaning properties and grip. As far as the aspect of grip is concerned, an aggravating factor is that the surgeon and user of the medical instrument wears gloves, usually made of latex, for hygiene reasons for personal protection and for protecting the patient. Therefore, the handle of the medical instrument has to be configured such that the handle surface portion in contact with the glove enclosing the surgeon's hand allows the application of a high frictional force without the glove slipping on the handle surface portion and without a finger accommodated in the glove slipping, said finger exerting a force on the handle surface portion. Although the handle surface portion has to be configured for the application of high static friction and, in the case of incipient slipping, to apply high sliding friction, the handle surface portion has to be designed such that it does not damage the surgeon's glove for example by sharp-edged transitions between the ribs and grooves. Furthermore, the handle surface portion has to be configured such that the glove does not stick to the handle surface portion or get stuck in the grooves in the handle surface portion when the surgeon's fingers come away from the medical instrument.
As far as the cleaning properties are concerned, in the case of medical instruments, importance is attached to the fact that contaminants, for example dried-on blood, adhering to the instrument, in particular to the handle surface portion that is provided with grooves or other depressions to achieve good grip and is thus particularly critical as far as cleaning properties are concerned, can be removed effortlessly. Since medical instruments, after rough cleaning, are subsequently steam-sterilized in an autoclave, the medical instrument should be designed such that, after steam-sterilization has taken place, no residual quantities of liquid collect in or on the instrument.
The generic medical instruments known from the prior art represent a compromise between the achievement of good grip of the instrument and good cleaning properties of the instrument.
In the case of the abovementioned first type of medical instruments configured in a generic manner, grip suffers when the force along the surface of the handle surface portion is not applied in a direction perpendicular to the grooves and ribs arranged parallel to one another, however. In this case, safe guiding of the medical instrument by the surgeon is jeopardized, since the surgeon's fingers applied to the grooves and ribs can slip in the direction of the respective longitudinal directions of the grooves and ribs. In the event of such slipping, there is also the risk that the ribs will have a knife-blade-like action and the glove will be damaged by the movement, brought about by slipping, in the longitudinal direction of the ribs. In addition, the deep grooves that meet one another at right angles are difficult to clean.
In the case of the abovementioned second type of medical instruments configured in a generic manner, the cleaning properties suffer especially from the fact that the rectangularly formed lands are completely surrounded by grooves which form a mesh-like pattern of groove portions that intersect at right angles and are thus difficult to clean. In addition, if the raised lands are at too narrow a spacing from one another, there is a risk of the glove getting stuck between the lands.
Furthermore, in the case of both types of medical instruments configured in a generic manner, liquid accumulations in or on the grooves of the instrument can occur after steam-sterilization.
DE 10 2007 047 059 A1 describes a medical instrument having a handle surface portion which can be provided with preferably elongate depressions. Grip appears to be in need of improvement.
Prior art outside the specialist field, in which different handle concepts for non-medical implements are explained, are described in US 2012/0137472 A1, US 2013/0175067 A1 and WO 2013/130365 A1.